Research Of Synergistic Antioxidant Among Highly Pigmented Agricultural Products

Phytochemicals which were rich in plants such as fruits and vegetables, have antioxidant and antiinflammation for the human health. They could prevent chronic diseases such as cardiovascular disease, cancer and diabetes. The synergistic antioxidant effect was found in the combination of different phytochemicals. Rational utilization of the synergistic effect can quickly improve its beneficial effect to human body. The main natural phytochemicals of daily consumption agricultural products(purple potato, eggplant, tomato and carrot) were the research object in this paper. In vitro chemical based and cellular antioxidant capacities were measured before and after the combination of samples. The main results were as follows:1. Ultrasonic assistance methods were used to extract the anthocyanins of purple potato and eggplant. The optimal extraction conditions were studied by the response surface methodology(RSM). The results were as follows: ultrasonic power 180 W, ultrasonic time 5 min, solvent/ sample ratio 30:1 m L·g-1, ethanol concentration 85%(eggplant). Ultrasonic power 270 W, ultrasonic time 40 min, solvent/sample ratio 30:1 m L·g-1, ethanol concentration 60%(purple potato). Under this condition, the anthocyanin contents of eggplant and purple potato were 5.18 mg/g and 0.356 mg/g, respectively.2. The anthocyanin contents and structures of eggplant and purple potato were measured by HPLC and LC-ESI-MS. The structures of anthocyanins were identified as: Delphinidin 3-fructoside(2.12 mg/100 g DW) and Petunidin 3-[6-(rhamnosyl)-2-(xylosyl)glucoside](0.52 mg/100 g DW)(eggplant);Petunidin 3-rutinoside-5-glucoside(6.51 mg/100 g DW) and Petunidin3-O-[6-O-(4-O-(4-O-(β-D-glucopyranosyl) feruloyl)-α-L-rhamnopyra-nosyl)-β-D-glucopyranoside]-5-O-[β-D-glucopyranoside](6.07 mg/100 g DW)(purple potato). One composition of eggplant anthocyanin was Delphinidin-3-(p-coumaroyl)-rutin-oside-5-glucoside(12.75 mg/100 g DW), which was identified by MS/MS. The carotenoid contents of tomato and carrotwere measured by HPLC. The lycopene content was 527.2 μg/g DW in tomato, the carotene content was 718.7 μg/g DW in carrot.3. Isobolographic analysis was used to assess the antioxidant interactions of different combinations. Most of the binary mixtures(LC-HE, LC-HP, HE-HP, LT-HE and LT-HP combinations) showed the synergistic antioxidant effects. In DPPH assay, the greatest antioxidant activity of agricultural product combinations was 1:9 LT-HP(EC50: 2.45±0.13 mg/m L), followed by 9:1 HE-HP(EC50: 3.62±0.12 mg/m L) and 1:9 LC-HE(EC50: 3.74±0.47 mg/m L). In ABTS assay, the greatest antioxidant activity of agricultural product combinations was 9:1 HE-HP(EC50: 4.20±0.10 mg/m L), followed by 7:3 HE-HP(EC50: 4.41±0.63 mg/m L) and 1:1 HE-HP(EC50: 5.35±0.85 mg/m L). Among these combinations, 1:1 LC-HE combination showed the highest synergistic antioxidant effects in DPPH assay(synergistic rate: 87.4%), and 7:3 LC-HE combination showed the highest synergistic antioxidant effects in ABTS assay(synergistic rate: 87.0%).4. 500 μmol/L H2O2 was used to treat H9c2 cell to establish the cell damage model. From the effects of single agricultural product extracts and combinations on H2O2-damaged H9c2 cell viability, it could be found that the single extract had protective effect for H9c2 cell. Moreover, the combinations possessed the synergistic protective effect.